Global Patent Index - EP 1013644 B1

EP 1013644 B1 20030423 - Method for production of hydroxylammonium phosphate in the synthesis of caprolactam

Title (en)

Method for production of hydroxylammonium phosphate in the synthesis of caprolactam

Title (de)

Methode zur Herstellung von Hydroxylammoniumphosphat in der Synthese von Kaprolactam

Title (fr)

Méthode de production de phosphate d'hydroxylammonium dans la synthèse de caprolactame

Publication

EP 1013644 B1 20030423 (EN)

Application

EP 99125633 A 19991222

Priority

US 22121198 A 19981224

Abstract (en)

[origin: EP1013644A1] A method for production of caprolactam. The method involves: (a) reacting air with ammonia gas in an ammonia conversion zone to produce nitric oxide; (b) oxidizing at least a portion of the nitric oxide to nitrogen dioxide to produce an NOx-rich process gas stream; (c) reactively absorbing the NOx-rich gas stream with phosphoric acid containing solution in an absorption zone to form nitrate ions; (d) contacting the nitrate ions with air in a degassing zone to produce a nitrate-rich aqueous process stream; (e) reducing the nitrate-rich aqueous stream with hydrogen in the presence of phosphoric acid to produce hydroxylammonium phosphate; (f) oximating the hydroxylammonium phosphate with cyclohexanone to produce cyclohexanone oxime; and (g) converting the cyclohexanone oxime to caprolactam. According to the invention, supplemental oxygen is added downstream of the ammonia conversion zone to increase the quantity and rate of formation of nitrogen dioxide in the NOx-rich process gas stream. <IMAGE>

IPC 1-7

C07D 201/06; C07D 201/10

IPC 8 full level

C07D 201/06 (2006.01); C07D 201/10 (2006.01)

CPC (source: EP)

C01B 21/1418 (2013.01); C07C 249/08 (2013.01); C07D 201/06 (2013.01); C07D 201/10 (2013.01); C07C 2601/14 (2017.05)

C-Set (source: EP)

C07C 249/08 + C07C 251/44

Citation (examination)

DE ROOJI ET AL: "Caprolactam, the HPO process", INF.CHIM., vol. 165, 1977, pages 121 - 128

Designated contracting state (EPC)

DE ES FR GB IT

DOCDB simple family (publication)

EP 1013644 A1 20000628; EP 1013644 B1 20030423; BR 9905965 A 20010123; CA 2293010 A1 20000624; CN 1155565 C 20040630; CN 1263090 A 20000816; DE 69907122 D1 20030528; DE 69907122 T2 20040226; ES 2197566 T3 20040101; ID 25716 A 20001102; KR 100480535 B1 20050406; KR 20000062222 A 20001025; US 6333411 B1 20011225

DOCDB simple family (application)

EP 99125633 A 19991222; BR 9905965 A 19991222; CA 2293010 A 19991222; CN 99126962 A 19991221; DE 69907122 T 19991222; ES 99125633 T 19991222; ID 991023 D 19991104; KR 19990060169 A 19991222; US 22121198 A 19981224